Method and system for automatically compensating for diagnosed banding defects prior to the performance of remedial service

Abstract

A system that extends the operational effectiveness of an image reproduction machine without requiring downtime for service by personnel includes a detection subsystem that monitors components of an image reproduction system for detecting a banding defect in the image reproduction system and an automated compensation subsystem for modifying operation of the image reproduction system to compensate for the detected banding defect so that the image reproduction system continues to generate images at an acceptable quality level. The automated compensation subsystem adjusts components and/or data used by image reproduction system to compensate for the identified banding defect without requiring immediate operator or service personnel intervention. This compensation may successfully attenuate the banding defect so that the image reproduction system continues to produce acceptable images without downtime while awaiting service by personnel. The system may also include a diagnostic subsystem for determining causes for a detected banding defect to further enhance the operation of the compensation system or to facilitate a repair action by a person.

1. A system for adjusting operation of an image reproduction system to compensate for banding defects comprising:
 a detection subsystem coupled to one of a charging subsystem, an exposure subsystem, a development subsystem, a transfer subsystem, and a fusing subsystem of an image reproduction system for monitoring the coupled subsystem for detection of a banding defect; 
 an automated compensation subsystem having an input data compensation subsystem coupled to a digital front end/image input terminal (DFE/IIT) of the image reproduction system to modify preprocessing of image data performed by the DFE/IIT to compensate for a detected banding defect, the automated compensation subsystem also being configured for modifying operation of the image reproduction system by adjusting one or more subsystems other than the subsystem being monitored by the detection subsystem to compensate for the detected banding defect so that the image reproduction system continues to generate images at an acceptable quality level; and 
 a diagnostic subsystem coupled to the detection subsystem to receive error identification data from the detection subsystem, the diagnostic subsystem being configured to identify a subsystem causing the detected banding error corresponding to the error identification data; and 
 the automated compensation subsystem further comprising a local compensation subsystem that is coupled to the diagnostic subsystem, the local compensation subsystem being configured to modify operation of the subsystem identified by the diagnostic subsystem as being a cause of the detected banding defect. 
 
   
   
     2. The system of  claim 1 , the detection subsystem being coupled to the exposure subsystem for monitoring an electrostatic image on a photoreceptor belt following the charging subsystem and the exposure subsystem of the image reproduction system and further comprising:
 an electrostatic voltmeter (ESV) attached to a mechanical scanner that moves across the photoreceptor belt, the ESV generating a voltage signal corresponding to electrostatic charge on the photoreceptor belt; 
 the detection subsystem using the voltage signal generated by the ESV to detect charging errors in a cross-process direction on the photoreceptor belt that indicate a banding defect has occurred in the electrostatic image on the photoreceptor belt; and 
 the automated compensation subsystem being configured to adjust the charging subsystem and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     3. The system of  claim 1 , the detection subsystem being coupled to the development subsystem for monitoring toner density in a developed electrostatic image on a photoreceptor belt following the development subsystem of the image reproduction system and further comprising:
 an enhanced toner area coverage (ETAC) sensor for generating a voltage signal corresponding to toner density on a photoreceptor belt and the detection subsystem using the voltage signal generated by the ETAC sensor for detecting process direction banding defects on the photoreceptor belt; and 
 the automated compensation subsystem being configured to adjust the charging subsystem, the exposure subsystem, and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     4. The system of  claim 1 , the detection subsystem being coupled to the development subsystem for monitoring toner density in a developed electrostatic image on a photoreceptor belt following the development subsystem of the image reproduction system and further comprising:
 an ETAC sensor attached to a mechanical scanner that moves across the photoreceptor belt to detect cross-process direction banding defects on the photoreceptor belt; 
 the detection subsystem using the voltage signal generated by the ETAC to detect charging errors in a cross-process direction on the photoreceptor belt that indicate a banding defect has occurred in the developed latent image on the photoreceptor belt; and 
 the automated compensation subsystem being configured to adjust the charging subsystem, the exposure subsystem, and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     5. The system of  claim 1 , the detection subsystem being coupled to the development subsystem for monitoring toner density in a developed electrostatic image on a photoreceptor belt following the development subsystem of the image reproduction system and further comprising:
 a full width array (FWA) sensor to measure image quality metrics for detecting process direction banding defects in electrostatic images on the photoreceptor belt; and 
 the automated compensation subsystem being configured to adjust the charging subsystem, the exposure subsystem, and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     6. The system of  claim 1 , the detection subsystem being coupled to the transfer subsystem for monitoring residual toner density on a photoreceptor belt following the transfer subsystem of the image reproduction system and further comprising:
 a full width array (FWA) sensor to measure image quality metrics for detecting process direction banding defects on the photoreceptor belt; and 
 the automated compensation subsystem being configured to adjust the charging subsystem, the exposure subsystem, the development subsystem, and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     7. The system of  claim 1 , the detection subsystem being coupled to the transfer subsystem for monitoring toner density on an intermediate belt following the transfer subsystem of the image reproduction system and further comprising:
 a FWA sensor to measure image quality metrics for detecting process direction banding defects on the intermediate belt; and 
 the automated compensation subsystem configured to adjust the charging subsystem, the exposure subsystem, the development subsystem, and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     8. The system of  claim 1 , the detection subsystem being coupled to the fusing subsystem for monitoring toner density on a sheet medium in proximity to the fusing subsystem of the image reproduction system and further comprising:
 a scanner for generating scanned images of test patterns; 
 a scanned image analyzer for detecting handing defects in the scanned images of the test patterns; and 
 the automated compensation subsystem being configured to adjust the charging subsystem, the exposure subsystem, the development subsystem, the transfer subsystem, and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     9. The system of  claim 1 , the automated compensation subsystem further comprising:
 a global compensation subsystem for modifying operation of a subsystem not identified by the diagnostic subsystem as being a cause of a detected banding defect. 
 
   
   
     10. The system of  claim 1  further comprising:
 a notification subsystem for notifying personnel of corrective action for addressing the detected banding defects. 
 
   
   
     11. A method for adjusting operation of an image reproduction system to compensate for banding defects comprising:
 monitoring one of a charging subsystem, an exposure subsystem, a development subsystem, a transfer subsystem, and a fusing subsystem in an image reproduction system; 
 detecting a banding defect at the image reproduction system subsystem being monitored; 
 compensating for the detected banding defect by adjusting preprocessing of image data performed by a digital front end/image input terminal (DFE/IIT) and by adjusting one of the charging subsystem, the exposure subsystem, the development subsystem, the transfer subsystem, the fusing subsystem not being monitored so that the image reproduction system continues to generate images at an acceptable quality level; 
 generating error identification data corresponding to the detected banding defect; 
 identifying with reference to the error identification data a subsystem causing the detected banding defect; 
 modifying operation of the identified subsystem. 
 
   
   
     12. The method of  claim 11 , the banding defect detection comprising:
 generating a voltage signal corresponding to an image generation parameter; and 
 detecting a banding defect that corresponds to the generated voltage signal. 
 
   
   
     13. The method of  claim 12 , the voltage signal generation comprising:
 generating a voltage signal that corresponds to toner density on a photoreceptor belt; and 
 detecting a cross-process direction banding defect that corresponds to the generated voltage signal. 
 
   
   
     14. The method of  claim 13 , the voltage signal generation comprising:
 moving an enhanced toner area coverage (ETAC) sensor across the photoreceptor belt to generate a voltage signal corresponding to toner density on the photoreceptor belt; and 
 detecting cross-process direction banding defects on the photoreceptor belt that correspond to the voltage signal generated by the ETAC. 
 
   
   
     15. The method of  claim 12 , the voltage signal generation comprising:
 moving an electrostatic voltmeter (ESV) across a photoreceptor belt to generate a voltage signal corresponding to electrostatic charge on a photoreceptor belt; and 
 detecting cross-process direction banding defects that correspond to the voltage signal generated by the ESV. 
 
   
   
     16. The method of  claim 11 , the DFE/IIT adjustment further comprising:
 adjusting a tonal reproduction curve used by the DFE/IIT; and 
 the method further comprising: 
 adjusting at least one of the charging subsystem, the exposure subsystem, the development subsystem, the transfer subsystem, and the fusing subsystem. 
 
   
   
     17. A system for adjusting operation of an image reproduction system to compensate for banding defects comprising:
 a detection subsystem coupled to one of a charging subsystem, an exposure subsystem, a development subsystem, a transfer subsystem, and a fusing subsystem of an image reproduction system for monitoring the coupled subsystem for detection of a banding defect; 
 an automated compensation subsystem having an input data compensation subsystem coupled to a digital front end/image input terminal (DFE/IIT) of the image reproduction system to modify preprocessing of image data performed by the DFE/IIT to compensate for a detected banding defect, the automated compensation subsystem also being configured for modifying operation of the image reproduction system by adjusting one or more subsystems other than the subsystem being monitored by the detection subsystem to compensate for the detected banding defect so that the image reproduction system continues to generate images at an acceptable quality level; 
 a diagnostic subsystem coupled to the detection subsystem to receive error identification data from the detection subsystem, the diagnostic subsystem being configured to identify a subsystem causing the detected banding error corresponding to the error identification data; 
 a local compensation subsystem that is coupled to the diagnostic subsystem, the local compensation subsystem being configured to modify operation of the subsystem identified by the diagnostic subsystem as being a cause of the detected banding defect; and 
 a notification subsystem for notifying personnel of corrective action for addressing the detected banding defects. 
 
   
   
     18. The system of  claim 17 , the detection subsystem being coupled to the exposure subsystem for monitoring an electrostatic image on a photoreceptor belt following the charging subsystem and the exposure subsystem of the image reproduction system and further comprising:
 an electrostatic voltmeter (ESV) attached to a mechanical scanner that moves across the photoreceptor belt, the ESV generating a voltage signal corresponding to electrostatic charge on the photoreceptor belt; 
 the detection subsystem using the voltage signal generated by the ESV to detect charging errors in a cross-process direction on the photoreceptor belt that indicate a banding defect has occurred in the electrostatic image on the photoreceptor belt; and 
 the automated compensation subsystem being configured to adjust the charging subsystem and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     19. The system of  claim 17 , the detection subsystem being coupled to the development subsystem for monitoring toner density in a developed electrostatic image on a photoreceptor belt following the development subsystem of the image reproduction system and further comprising:
 an enhanced toner area coverage (ETAC) sensor for generating a voltage signal corresponding to toner density on a photoreceptor belt and the detection subsystem using the voltage signal generated by the ETAC sensor for detecting process direction banding defects on the photoreceptor belt; and 
 the automated compensation subsystem being configured to adjust the charging subsystem, the exposure subsystem, and the DFE/IIT in response to a banding defect being detected by the detection subsystem. 
 
   
   
     20. The system of  claim 17 , the detection subsystem being coupled to the development subsystem for monitoring toner density in a developed electrostatic image on a photoreceptor belt following the development subsystem of the image reproduction system and further comprising:
 an ETAC sensor attached to a mechanical scanner that moves across the photoreceptor belt to detect cross-process direction banding defects on the photoreceptor belt; 
 the detection subsystem using the voltage signal generated by the ETAC to detect charging errors in a cross-process direction on the photoreceptor belt that indicate a banding defect has occurred in the developed latent image on the photoreceptor belt; and 
 the automated compensation subsystem being configured to adjust the charging subsystem, the exposure subsystem, and the DFE/IIT in response to a banding defect being detected by the detection subsystem.